School of Energy Science and Engineering, Henan Polytechnic University
State Collaborative Innovation Center of Coal Work Safety and Clean-Efficiency Utilization

目的目的针对高应力软岩巷道存在变形量大、变形时间长、可锚性差等问题,目前多采用可接长注浆锚杆进行改性支护加固,如何提升其强度和抗变形能力成为控制围岩大变形的关键。为了提高可接长注浆锚杆的强度,方法方法基于可接长注浆锚杆的螺纹连接特性,采用螺纹连接段工作力学性能理论分析和数值模拟相结合的方法,分析连接段的不同失效模式以及螺纹类型对锚杆力学性能的影响,对比常见不同类型螺纹的连接强度,分析连接段的连接长度、螺纹螺距和连接件外径对于锚杆强度和抗变形能力的影响。结果结果结果表明:螺纹连接段失效模式可分为螺纹滑脱破坏、连接件拉断破坏和锚杆拉断破坏,不同失效模式取决于螺纹抗剪强度、锚杆与连接件的最小抗拉强度。当连接段长度较短,连接段呈现螺纹滑脱破坏时,随着连接长度增加,连接段薄弱点由螺纹截面转为锚杆螺纹根部,呈现锚杆拉断破坏。随着螺纹螺距增加,峰值载荷先上升后下降,螺距为2.0mm时达到载荷峰值。随着连接件外径增加,螺纹连接段失效模式由连接件拉断破坏变为螺纹滑脱破坏,最后转变为锚杆拉断破坏,连接强度呈先上升后下降的趋势。结论结论以外径22mm,内径12mm的中空注浆锚杆为例,连接长度20mm、螺纹螺距2.0mm、连接件外径28mm时,锚杆连接段抗拉强度最佳,载荷峰值为118.8kN,可以满足高应力软岩巷道的支护要求。

Objectives To address the challenges of large deformation, prolonged deformation periods, and poor anchorage in high-stress soft-rock tunnels, extendable grouting bolts are commonly used as an im⁃proved support and reinforcement method. Enhancing the strength and deformation capacity of these bolts has become critical for controlling the significant deformation of surrounding rock. Methods To improve the strength of extendable grouting bolts, theoretical analysis and numerical simulations were employed to study the threaded connection characteristics and failure modes of the connecting segments. The effects of different thread types on the mechanical properties of the bolts were analyzed, and the connection strength of commonly used thread types was compared. The influence of connection length, thread pitch, and con⁃nector outer diameter on the strength and deformation capacity of the bolts was evaluated, leading to the identification of optimal parameter combinations. Results The findings reveal three failure modes for the connecting segments: thread slip failure, connector pull-off failure, and bolt pull-off failure. These modes depend on the thread shear strength and the minimum tensile strength of the bolts and connectors. When the connection length is short, thread slip failure occurs; as the connection length increases, the weak point transitions from the thread cross-section to the bolt thread root, resulting in bolt pull-off failure. In⁃creasing the thread pitch initially raises the peak load, which reaches a maximum at a pitch of 2.0 mm be⁃fore declining. Similarly, increasing the connector outer diameter changes the failure mode from connector pull-off failure to thread slip failure, and eventually to bolt pull-off failure, with the connection strength peaking before declining. Conclusions Taking a hollow grouting bolt with an outer diameter of 22 mm and an inner diameter of 12 mm as an example, the optimal tensile strength of the connecting section is achieved when the connection length is 20 mm, the thread pitch is 2.0 mm, and the connector outer dia-meter is 28 mm. Under these conditions, the peak load reaches 118.8 kN, meeting the support require⁃ments of high-stress soft-rock tunnels.

国家自然科学基金资助项目(52074102);河南省自然科学杰出青年基金资助项目(212300410006);河南省高校科技创新团队项目(23IRTSTHN007)

刘少伟,张玮钰,贺德印.可接长注浆锚杆连接段破坏失效模式及参数优化[J].河南理工大学学报(自然科学版),2025,44(2):1⁃9.

LIU S W, ZHANG W Y, HE D Y. Damage failure mode and parameter optimization of the connecting section of ex⁃tendable grouting bolts[J]. Journal of Henan Polytechnic University(Natural Science), 2025, 44(2): 1-9.